Automatic guns can be generally classified, according to their mode of operation, as either self-powered or externally powered. Self-powered automatic guns utilize recoil or high pressure barrel gasses caused by firing to cycle operating mechanisms which load and fire the gun. In particular, a mechanically actuated firing pin strikes a primer cap at the rear of the weapon cartridge, to thereby ignite the propellant for the projectile. The bolt is driven rearward by the propellant gases shortly after the firearm is fired. This action, i.e., “cycling” of the weapon, pulls the spent cartridge from the chamber and ejects the empty shell. Once the bolt reaches the end of travel, the bolt suddenly stops. A spring then provides forward bias to drive the bolt forward and pushes a new cartridge in the chamber.
Self-powered automatic guns are inherently more portable or mobile than externally-powered guns, in which operating mechanisms of externally-powered guns are driven by actuators or motors independently of firing forces, are, therefore, usually preferred for small arms, machine guns and light cannons. However, for larger cannons, external powered actuators are sometimes needed to operate the weapon systems, including loading, cycling, and gun aiming movement. Since such larger guns are difficult to implement as self-powered guns, because of shell size, weight and size of moving operational gun parts, larger guns have typically been constructed to be contrast.
However, automation of guns in general, and large guns in particular, such as those used in tanks and armored vehicles in particular, has heretofore usually been limited to the automation of a single operational function. For example, an actuator has been used for opening and closing the breech, or loading shells into an open breech. A human operator has ordinarily functioned to operationally bridge the separately automated functions. Firing rates of such guns, in which an operator performs the key role as system integrator, have thus been limited by the operator's skill and ability in perceiving the operational status of the automated gun hardware and in deciding when the operating commands should be given to initiate each successive automated operation.
Many problems encountered in mechanizing (automating) large guns are attributable to the fact that the guns were not originally designed for automatic operation. Thus, design of such guns has principally involved adaptations of pre-existing, manually operated guns. As a consequence, their automation has usually consisted of little more than the retrofitting of existing gun hardware. Although some limited success has been achieved through such retrofitting, the resulting gun systems have, at best, been awkward and non-optimal in terms of gun operating speeds and firing rates, and also in terms of system cost and reliability.
Moreover, control systems for previously automated large caliber guns have controlled only a few sequential steps, and have been implemented by simple and/or logic elements, flip-flop circuits typically being used to control actuating motors, or solenoids. Further, the progression from one separately automated step to another has heretofore been sequenced by pre-set timers, so that gun operation proceeds in accordance with a fixed time schedule. Reliance upon such timing schedules, however, can cause serious problems because operating times may, in fact, vary widely in the same gun according to conditions. For example, the time required to advance shells to the gun typically varies according to the number, and hence the mass, of shells which must be advanced.
Operating times also depend upon such factors as how clean or how well lubricated the gun is, the extent of gun wear and the operating temperatures. If the gun design does not take such time-affecting variables into consideration, one operating step may be initiated before a preceding step is completed, with potentially disastrous consequences. A particular event which is difficult to provide for in a fixed timing schedule is shell firing time. Typically shells fire within a few milliseconds after firing impact or, as the case may be, electrical contacting. Propellant combustion ordinarily occurs within the next few milliseconds and casing pressure is typically reduced to a safe casing extraction level in several more milliseconds. Thus, only about 10 to 20 milliseconds of firing “dwell time” is ordinarily required.
However, in system use, a few shells, presumably due to manufacturing defects, do not fire as expected. Instead, there is a brief delay after impact or electrical contact before ignition occurs. This phenomenon is commonly referred to as a “hang fire” condition. If a hang fire causes a shell to fire after a timed casing extraction has begun, the gun may be destroyed and operating personnel may be injured. On the other hand, if worst case hang fires are considered in establishing the gun operating time schedule, gun performance will be compromised. If the timing schedule also takes into account all other possible worst case conditions affecting gun operating times, the firing rate will be drastically reduced over that possible under most operating conditions. As a result, the automatic operation of a gun on a fixed timing schedule is generally unsatisfactory.
Further, currently, robotic devices have begun to be commonly used in police and military applications. Systems for mounting firearms on such robotic devices have been recently developed. These systems for mounting firearms on robotic devices are designed, however, to utilize conventional gas-powered (self-powered) weapons. In particular, the weapon, such as a conventional shotgun or an M-4, is removably mounted in the system, wherein the system allows a user to wirelessly control mechanical mechanisms to release the weapon safety switch and pull the trigger.
However, such conventional systems for mounting firearms on robotic devices have several drawbacks. First, an enemy can disable the robotic device, remove the firearm from the mounting system, and utilize the firearm against the controller of the robotic device and/or friendly forces. Second, as discussed above, self-powered weapons tend to periodically jam, and require human interaction to clear the jam when same occurs, placing the operator in a potentially fatal situation. Third, by requiring placement of a conventional weapon in the mounting system, a soldier usually must place his weapon into the mounting system of the robotic device during operation thereof, which personally places the operator in a vulnerable position during operation of the robotic device.
It is, therefore, an object of the present invention to provide an externally-powered, electrically actuated weapon, in which all firing operations of the weapon can be remotely externally operated.
It is another object of the present invention is to provide an externally-powered, electrically actuated weapon which, if removed from the device upon which the weapon is mounted, such as a robotic device, is inoperable.
A further object of the present invention is to provide an externally-powered electrically actuated weapon which operates on a strict logic basis, rather than on a fixed timing schedule, which stops operating if pre-established logic conditions are not met, and which provides status and malfunction information to the gun operator.
Another object of the present invention is to provide an externally-powered, electrically actuated weapon in which initiation of each operational step is conditioned on specific moving parts of the gun being in specific positions.